Arbitrary File Download Via MSOHTMED.EXE — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-08-19 / 2023-11-09.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: bac6a04d85ce0e57e7fd3d4b09c50312e745e8f2e7077c18bece985ea5459022

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Arbitrary File Download Via MSOHTMED.EXE
id: 459f2f98-397b-4a4a-9f47-6a5ec2f1c69d
status: test
description: Detects usage of "MSOHTMED" to download arbitrary files
references:
    - https://github.com/LOLBAS-Project/LOLBAS/pull/238/files
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-19
modified: 2023-11-09
tags:
    - attack.execution
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\MSOHTMED.exe'
        - OriginalFileName: 'MsoHtmEd.exe'
    selection_cli:
        CommandLine|contains:
            - 'ftp://'
            - 'http://'
            - 'https://'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/LOLBAS-Project/LOLBAS/pull/238/files